IP-10质粒联合吉西他滨抗肿瘤作用的实验研究

Antitumor Effects of Interferon-γ-inducible Protein 10 Combined with Gemcitabine

背景与目的:IP鄄10是α趋化因子家族成员,IP鄄10具有抗肿瘤血管作用,表现为抑制新生血管分化成毛细血管。研究表明,化疗与抗肿瘤血管治疗结合具有协同作用。本研究拟用IP鄄10质粒与化疗药物吉西他滨联合治疗肿瘤,观察其抗肿瘤作用。方法:质粒pBLAST鄄IP鄄10转化至大肠杆菌中,经扩增后,制备并纯化质粒。采用BALB/c及C57BL/6小鼠,分别建立H22肝癌及Lewis肺癌肿瘤模型。IP鄄10质粒及生理盐水肌肉注射,吉西他滨腹腔注射。收集小鼠血清,ELISA方法检测血清中IP鄄10蛋白表达;观察肿瘤体积变化、小鼠存活期及不良反应;肿瘤组织微血管免疫组化染色,确定微血管密度;TUNEL法检测肿瘤组织中细胞凋亡。结果:IP鄄10质粒肌注后小鼠血清中IP鄄10蛋白表达于第2周达高峰[(16.8±3.6)ng/ml],至第5周仍持续有较高水平表达[(14.0±2.1)ng/ml]。IP鄄10质粒联合吉西他滨组小鼠肿瘤体积较对照组显著受抑甚至消退,在接种肿瘤细胞后第9周联合给药组小鼠存活率为90%,明显高于其他各组(IP鄄10质粒组55%,吉西他滨组以及生理盐水组为0%)(P<0.005);各组小鼠均未出现明显的不良反应。肿瘤组织内微血管密度在联合给药组为15.8±2.4,显著低于其它各组(IP鄄10组45.6±2.0,吉西他滨组50.2±3.5和生理盐水组51.3±3.0)(P<0.01)。在接种肿瘤细?

BACKGROUND & OBJECTIVE: Interferon-γ-inducible protein 10 (IP-10), a member of α-chemoattractant family, is an inhibitor of tumor angiogenesis. C hemotherapy combined with antiangiogenic therapy has synergistic effects. This s tudy was designed to explore antitumor effect of IP-10 combined with gemcitabine in tumor-bearing mice. METHODS: pBLAST-IP-10 was transferred into E.coli to pre pare and purify plasmid IP-10. Hepatocarcinoma H22 model was established in BALB /c mice; Lewis lung cancer LL/2 model was established in C57BL/6 mice. The mice were divided into 4 groups, and treated with IP-10, gemcitabine, IP-10 plus gemc itabine, and normal saline (control), respectively. Protein level of IP-10 in se rum was detected by ELISA. Survival rate of mice, tumor volume, and side effects of treatment were observed. Microvessel density (MVD) of tumor tissue was detec ted by immunohistochemistry. Apoptosis of tumor cells was detected by TUNEL meth od. RESULTS: After treatment of IP-10, IP-10 protein reached the peak level of ( 16.8±3.6) ng/ml at the 14th day, and remained a high level of (14.0±2.1) ng/ml at the 35th day. Compared with the controls, tumor volume of mice in the combin ation therapy group had significant regression, or disappeared. Nine weeks after inoculation of tumor cells, survival rate of mice was significantly higher in c ombination group than in IP-10, gemcitabine, and control groups (90% vs. 55%, 0% , and 0%, P < 0.005). No obvious side effects were observed. MVD of tumor tissue s was significantly lower in combination group than in IP-10, gemcitabine, and c ontrol groups (15.8±2.4 vs. 45.6±2.0, 50.2±3.5, and 51.3±3.0, P < 0.01). At the 35th day after inoculation of tumor cells, apoptosis index was significantly higher in combination group than in IP-10, gemcitabine, and control groups (85. 5±10.2 vs. 21.4±5.5, 8.4±2.0, 4.2±0.7, P < 0.01). CONCLUSION: Therapy of IP- 10 combined with gemcitabine has significantly synergistic antitumor effect comp ared with IP-10 or gemcitabine alone.